Devices and methods for nerve stimulation

Abstract

Methods and devices for stimulating a nerve in a patient include emitting an electrical signal near a spinal nerve within the patient such that the patient experiences at least some pain relief. The methods include varying an electric field such that burst periods and constant periods are created. The electric field has a charge that alternates between positive and negative during the burst periods and a charge with a magnitude of zero during the constant periods.

The invention claimed is: 
     
       1. A method comprising:
 generating an electrical signal within a housing having a lead extending therefrom; 
 varying the electric field with a signal generator within the housing such that burst periods and constant periods are created, wherein the electric field has a charge that alternates between positive and negative during the burst periods, wherein the charge of the electric field alternates between positive and negative 2 times to 20 times during each burst period, and wherein the charge of the electric field is constant during each constant period; 
 positioning the lead near, or in operational proximity to, a spinal nerve within a patient; and 
 emitting the electrical signal via the lead towards the spinal nerve such that an electric field is generated near the spinal nerve such that the patient experiences at least some pain relief. 
 
     
     
       2. The method of  claim 1 , wherein the lead includes an electrode, and further comprising positioning the electrode near, or in operational proximity to, the spinal nerve and applying a voltage to the electrode such that the electric field is generated. 
     
     
       3. The method of  claim 2 , further comprising varying the voltage such that the electric field includes the burst periods and the constant periods. 
     
     
       4. The method of  claim 1 , wherein the charge of the electric field alternates between positive and negative 4 and 10 times during each burst period. 
     
     
       5. The method of  claim 1 , wherein the burst periods have a frequency of about 1 to about 100 Hz. 
     
     
       6. The method of  claim 1 , wherein each burst period has a duration of less than about 20,000 microseconds. 
     
     
       7. A device comprising:
 a housing; 
 a lead extending from the housing, wherein the lead is configured to be positioned near, or in operational proximity to, a spinal nerve; and 
 a source of energy positioned within the housing, wherein the source of energy is operably coupled to the lead; 
 a signal generator configured for generating an electrical field such that the electrical field is emitted via the lead towards the spinal nerve such that that a patient experiences at least some pain relief, wherein the signal generator is configured to vary the electrical field to create burst periods and constant periods, wherein the electric field has a charge that alternates between positive and negative during the burst periods, wherein the charge of the electric field alternates between positive and negative 2 and 20 times during each burst period and wherein the charge of the electric field is constant during each constant period. 
 
     
     
       8. The device of  claim 7  further comprising one or more electrodes coupled to the source of energy, wherein the source of energy applies a voltage to the electrode(s) to generate the electric field. 
     
     
       9. The device of  claim 7 , wherein the burst periods have a frequency of about 1 to about 100 Hz. 
     
     
       10. The device of  claim 7 , wherein the electric field emitted during the constant periods has a magnitude of about zero. 
     
     
       11. The device of  claim 7 , wherein each burst period has a duration of less than about 20,000 microseconds.